• Applied Microscopy
• /
• 제25권4호
• /
• pp.26-51
• /
• 1995

The present study was designed to examine effect of long term weight-training on aging atrophy in the rat skeletal muscle. Male rats of 8, 15, and 24 month old were used. Each age groups included control and weight-training for 5 months by using body press apparatus. The histo- and cytochemical, ultrastructural and stereological changes in aging skeletal muscles of the rat were observed in the present study. During the training period the body weight and muscular weight in all groups except the rectus femoris and the gastrocnemius in young age groups remained constant, but muscular weights were increased in the rectus femoris and the gastrocnemius muscles in young age groups. In trained rat, the volume density of muscle fiber type IIA and IIB were increased, but those of type IIC was decreased. Type I remained constant in 8 and 15 month old age groups, but reduced in the tibialis anterior and the gastrocnemius muscles in the 24 month old groups. Some histotological and ultrastructural changes associated with age were found: numerical increase of cytiplasmic vacuoles, lysosomes, lipofuscins, and irregularity of myofibrils. At 24 month old groups some unusual formation of contraction band and muscle splitting were observed. After weight-training, ultrastructural degenerative changes occured in the type I muscle fiber, such as splitting of muscle fiber, disorganization of myofilaments, swelling of mitochondria, accumulation of many lipid droplets, appearance of many lysosomes and residual bodies and necrotic fibers, in the old age groups. But, in the type II muscle fibers hypertrophy of muscle fiber appeared without any noticible damage as the type I. The activities of $Mg^{++}$ -ATPase decreased with age and this enzyme activities in the trained rat were significantly decreased with age. Activities of the acid phosphatase were increased with age and significantly in the trained rat. In stereological analysis, volume density of the myofibrils and the tubular system were increased, on the other hand there mitochondrial capacity was decreased. These experimental results suggested that old rats are not susceptible to be affected by weight-training as young rats, and that physical capacity of the rats must be considered when old rats are exercised for training.

• The Korean Journal of Physiology and Pharmacology
• /
• 제21권6호
• /
• pp.651-656
• /
• 2017

Ursolic acid (UA) supplementation was previously shown to improve skeletal muscle function in resistance-trained men. This study aimed to determine, using the same experimental paradigm, whether UA also has beneficial effects on exercise-induced skeletal muscle damage markers including the levels of cortisol, B-type natriuretic peptide (BNP), myoglobin, creatine kinase (CK), creatine kinase-myocardial band (CK-MB), and lactate dehydrogenase (LDH) in resistance-trained men. Sixteen healthy participants were randomly assigned to resistance training (RT) or RT+UA groups (n=8 per group). Participants were trained according to the RT program (60~80% of 1 repetition, 6 times/week), and the UA group was additionally given UA supplementation (450 mg/day) for 8 weeks. Blood samples were obtained before and after intervention, and cortisol, BNP, myoglobin, CK, CK-MB, and LDH levels were analyzed. Subjects who underwent RT alone showed no significant change in body composition and markers of skeletal muscle damage, whereas RT+UA group showed slightly decreased body weight and body fat percentage and slightly increased lean body mass, but without statistical significance. In addition, UA supplementation significantly decreased the BNP, CK, CK-MB, and LDH levels (p<0.05). In conclusion, UA supplementation alleviates increased skeletal muscle damage markers after RT. This finding provides evidence for a potential new therapy for resistance-trained men.

• PNF and Movement
• /
• 제13권4호
• /
• pp.181-188
• /
• 2015

Purpose: This study aimed to examine the effects of proprioceptive neuromuscular facilitation (PNF) lower extremity patterns combined with elastic bands applied to stroke patients diagnosed with hemiplegia through self-training using the non-paralyzed side approach and the paralyzed side approach, and to investigate the differences in the effects. Methods: Nine chronic stroke patients who were being treated not more than twice a week at H, K, R, and C hospitals located in Gangwon-do, performed self-training for 16 minutes, two times per day for four weeks between August and October 2015. The subjects' balance ability was measured using the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and the Timed Up and Go (TUG) test before the experiment and four weeks later. Among the statistical methods, paired t-tests were conducted for intra-group comparison of the measurements taken before and after the experiment, and independent t-tests were conducted for inter-group comparison of the ex post facto values. The statistical significance level was set to 0.05. Results: When the lower extremity patterns were applied to the non-paralyzed side group and the paralyzed side group, significant intra-group differences were observed for the Tetrax stability index, the weight distribution index, the Berg Balance Scale (BBS), and Timed Up and Go (TUG) tests (p<0.05); however, the inter-group comparisons showed no significant differences. Conclusion: The non-paralyzed side approach was found to be easy for patients to participate in and it also affected the patients' paralyzed side. Although the paralyzed side approach produced good exercise effects in a short period of time, it could result in adverse effects, such as a decrease in motivation and self-confidence. Therefore, these approaches are considered to be more effective when they are selectively applied depending on the purpose of the intervention and the degree of a patients' participation.